Technical Field
The present disclosure relates to a carbon dioxide (CO2) absorbent composition and a method for capturing CO2. More particularly, the present disclosure relates to a CO2 absorbent composition including an amino acid salt and a method for capturing CO2 using the same.
Description of Related Art
In recent years, the greenhouse effect affects the whole world significantly. The extreme weather is getting worse globally, which is caused by the increasing atmospheric CO2 concentration due to the overuse of fossil fuels. The atmospheric CO2 concentration before the Industrial Revolution is about 280 ppm. However, in June 2016, the average of atmospheric CO2 concentration detected by the monitoring station of Mauna Loa in Hawaii is up to 404.08 ppm. The increase degree of the atmospheric CO2 concentration is significant. For reducing the global warming, how to reduce the atmospheric CO2 concentration becomes one of the most important issues.
The main source of the atmospheric CO2 is the burning of fossil fuels. All countries are committed to develop the renewable energy for replacing the thermal power plant, such as coal-fired power plant. However, according to the estimation of BP Statistical Review of World Energy, among the fossil fuels, the amount of the coal still can be used more than 100 years. Due to the low cost, it is inevitable to generate electricity by burning fossil fuels. If the emission of CO2 generated from the burning of fossil fuels can be effectively reduced, the atmospheric CO2 concentration can be reduced significantly.
Nowadays, the main CO2 capture technology applied to thermal power plant is chemical absorption method. When using the chemical absorption method, the high-temperature flue gas generated by burning the fossil fuels, such as coal and natural gas, is first cooled down and the impurities are removed. Then the CO2 of the flue gas is absorbed with an amine absorbent or an alcohol amine absorbent. Afterwards, the absorbent is introduced into a reboiler to regenerate the high purity CO2, and the CO2 can be further fixed or reused. However, the chemical absorption method has the drawbacks of high regeneration energy and bulky equipment. Take the monoethanolamine (MEA) for example, MEA is the most widely used CO2 absorbent, and the regeneration energy thereof is 3.2-5.5 GJ/tonne of CO2.
To sum up, how to improve the CO2 capture technology for preventing the drawbacks of high regeneration energy and bulky equipment and providing other advantages, such as low dissolved oxygen value (DO) and prolonging the lifetime of the absorbent, is the goal of the relevant industry and academia.